Artificial arm



ARTIFICIAL ARM Filed April 4, 1945 Patented Oct. 7, 1947 ARTIFICIAL ARM Application April -4 1945, `Serial No. 586,504

4 v.Claims- This vinvention relates to :artificial armsandhas special reference vto an artificial arm for use in connection with yamputations above the elbow joint.

More particularly `the invention relates to an elbow joint i or artificial arms.

One important object of the invention is to providean improved construction of such a joint.

A ysecond important object of the invention is to provide an improved 4joint for this purpose wherein the pivotal member of the joint will be so reinforced .as to ensure long life.

A third important object of the invention is to provide a joint gf this character wherein the upper and lower a-rm sections are pivoted tof getherand may be held in desired angular rela,- tion.

Affcurtb `impclcarli .cbiect cf :the invention yis tc lprovide joint .of this character wherein the lower arm section may be allowed to swing freely from the upper arm section.

A fth important object of the invention is to provide a novel arrangement of controlling device for such an arm.

With the above and other objects in view, as will hereinafter be apparent, the invention consists in general of certain novel features of construction and combinations of parts hereinafter fully described, illustrated in the accompanying drawings, and particularly claimed.

In the accompanying drawings, like characters of reference indicate like parts in the several views and:

Fig. 1 is a longitudinal median section through a form of elbow joint embodying this invention.

Fig. 2 is a section on the line 2 2 of Fig. 1.

Fig. 3 is a fragmentary section on the line 3-3 of Fig. 1.

Fig. 4 is a section on the line 4-4 of Fig. 1.

In those cases in which amputation has taken place at the upper arm it becomes necessary to replace the elbow joint and to that end the means shown in Figs. l to 4 are used. In this arrangement I is shown as of metal and a cuff I I ts the stump of the upper arm and forms a socket therefor. At its lower end this cuff I| carries a hollow metal member I2 the lower end of which is substantially semicylindrical in form. At each side of the member I0 there is provided a strap I3 which extends upwardly beyond the member I0 to a position opposite the axial center of the cylindrical lower end of the member I2. At this point the member I2 is provided on each side with a socket I4; also each member I3, has at its upper end a boss I5 which fits in the respective socket '14 Where te? device is @55cmbled. A pivot pin I6 passes thruthe pivot ends of the members I3, being prcvisicd at cnc ,ccd with .c screw head .l 1 The other end has e thrcadcdrccess L8 and@ .Screw I 9 is .Screwed into this recess to prevent .the lues l5 of the members lf3 `fnml springing .cui cf the sockets. On thc cylindrical portion .of thcmcmbcr l2 .is mclmtcd c rciniorcine plate .211 and @series cf spaccd cpc@- ines 21 extend thru this reinforcing plate and the cylindrical portion of .the member I?- ;Tlcfc the straps 13 `and thc 4sicles cf the member I9 passes aqpvct srewl ivhcrecn is mounted a beucrank `leverfz? having at ,cnc cod a finger 24 .engageable in and .discnsageablc fr cm .thc openings A2| by biasing of the Vlever 213. A screw 25 .passes thru the hub of the lever ,23am engages in `.the usualgroovein shaitZZ so as to pre;- vcnt ilonsitudinalfslipping of the lever on the shaft while allowing free rotary movement on such shaft. A coiled compression spring 26 urges the lever 23 to bias in such direction as to cause engagement of the iinger 24 in one of the openings 2|. It will here be noted that the end of the reinforcement 20 is bevelled as at 21 so that the finger 24 will not be caught iby the end of this member in the event that the arm is rotated too greatly. On the member I0 is secured a plate 28 and thru the member I0 and this plate extends a key-hole slot 29. A push rod 30 passes thru this slot and has its lower end pivoted to the bell crank 23 as clearly shown in Fig. l. Also a push button 3| is screwed into the upper end of the rod 30 in such manner as to leave space between the head of the push button and the upper end of the member 30. This shank so formed that it can pass into the narrow end of the key-hole slot 29 while the rod 30 cannot pass thru such narrow end but can pass thru the wide end. Consequently when the push button 3 is pressed to release the linger 24 from engagement with a hole 2| it may be held from such engagement by swinging the rod 30 toward the narrow end of the key-hole slot as indicated in dotted lines in Fig. 1 or may be allowed to remain at the wide end and released. With the rod 30 in the dotted line position the upper and lower joints of the artificial arm can swing freely so that a person while walking may have the natural swinging movement between the upper and lower arms. On the other hand, if it is desired to hold the upper and lower arm in some xed position the rod 30 is moved to the larger end of the key-hole slot and released. The finger 24 will then drop into one of the holes l2| 2,428,632 Y *Y .v

centric to the pivotal connection, said end having a series of openings spaced therearound, a pawl pivoted in the other section and spring pressed toward said arcuate end, a finger on said pawl adapted to enter selectively said openings, a

push rod connected to said pawl tomove it against the spring action when depressed, said pawl carrying section having a keyhole slot through which the push rod extends, said push rod being freely movable through the larger end of the slot and shouldered to restrain movement through the smaller end of said slot. Y 1 Y 2. In an artificial arm, anupper arm section constituting a socket for the end of an amputated arrn,ra lower arm section, straps extending longitudinally of each section at thefsides thereof, annular socket members fixed to one of said sections at the pivotal axis thereof, bossesl carried by the straps of the othersection and fitting in said socket members, and a threaded pin extending through side bosses and holding the same against release from said socket members.

3. In an artificial limb, an upper armsection including a hollowflower end portion of substantially hemispherical form, a pivo-t shaft extending diametrically -through saidend, a lower arm section pivoted on said shaft,y a reinforcing band eX- *tending around said hollow lower end in-a plane `at right angles to said shaftysaid band and end having spaced openings therein, a shaft carried Y by said lower arm parallel to the iirst'shaft, a

having spaced openings therein, a shaft carried by said lower arm parallelto the first shaft, a bell crank lever pivoted at its angle on'the second shaft and having an end portion adapted Se1ec tively to enter said openings, spring means urging said end portion against said band, and means to bias spring means against engaging said open ings.

including a hollow lower end portion'of substan- Y tially hemispherical form, a pivot shaft extending diametrically through said end, a Vlower arm section pivoted on said shaft, a reinforcing band extending around said hollow lower end in a plane at right angles to said shaft, said band and end bell crank lever pivoted at its angle on the second shaft and having an end portion adapted se..

lectively to enter saidopenings, spring means f urging said end portion against said band, said REFERENCESCITED Y The following referencesare of record in the file of this patent:

UNITED STATES 'PATENTS Number Name Y Date 1,301,575 Krawczynski Apr. 22, 1919 1,402,709 Blatchford' Jan. Y3, 1922 1,914,882

Caron June 20, 1933 4. In an artificial limb, an upper arm section 

